Heretofore, awnings of this type have been designed and constructed for use on the outside of a window, or over a porch or balcony or the like. Such awnings comprise a frame carrying a plurality of pivoted louver vanes which may be opened or closed to admit light, improve air flow, or exclude rain, etc.
A major problem with known movable awning louvers is their tendency to change position when common environmental forces are applied to them. The magnitude of the forces generated by wind and rain and effective on an awning may be quite large and cause unwanted louver angle changes, excessive noise from the flapping of the louvers, and premature failure of the awning structure due to the dynamic stresses created. Although prior awnings of this type have embodied various means for adjusting the louver vane angle by the use of lever arms, chains, and toggle joints, they have not provided a construction wherein the louvers are locked in their selected position to insure against unwanted louver displacement.